Previous Year UPSC Questions

Explanation

Capillarity, also known as capillary action, is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. Capillarity is crucial in various natural and artificial processes, where the balance of forces drives the liquid into confined spaces.

Option (a) is correct: The tiny pores in the blotting paper act as capillaries and draw the ink through them.

Option (b) is incorrect: This is primarily due to hydrostatic pressure and not capillary action. Water moves through soil and rock layers due to pressure gradients rather than the effects of surface tension.

Option (c) is correct: This is due to capillarity. The fine fibers in the cloth act as capillaries, drawing water into them.

Option (d) is correct: Capillary action, along with transpiration pull and root pressure, helps move water through the tiny xylem vessels in plants.

Explanation

Assertion (A) is true: The fiscal deficit is the difference between the government’s total expenditure and its total non-debt receipts (revenue receipts plus non-debt capital receipts). It represents the total borrowing requirement of the government. Budgetary Deficit can be termed as the excess of the total government expenditure over the total revenue generated in a financial year. The fiscal deficit is always greater than or equal to the budgetary deficit. This is because the fiscal deficit includes all borrowings, while the budgetary deficit only looks at the gap in the revenue account. The fiscal deficit includes borrowing to finance capital expenditure (investments in infrastructure, etc.), which is not part of the revenue account. Reason (R) is false: This is because the fiscal deficit is not solely borrowing from the Reserve Bank of India. It includes borrowing from the public, financial institutions, and external sources, as well as other liabilities like market loans and securities.

Explanation

Cryogenics is a branch of physics that focuses on the production and study of materials and phenomena at extremely low temperatures, typically below -150 degree celsius. At these temperatures, materials exhibit unique physical properties that are not observed under normal conditions.

Option (a) is correct: Cryogenics has three major applications:

Space Travel: Used in rocket propulsion with cryogenic fuels like liquid hydrogen (LH2) and liquid oxygen (LOX) for efficient and high-energy space missions. Surgery: Applied in cryosurgery to destroy diseased tissue using extremely low temperatures, benefiting fields like dermatology and oncology. Magnetic Levitation: Enables superconducting magnets in Maglev trains and devices by cooling materials to achieve zero electrical resistance, allowing frictionless transportation.

Explanation

Surendranath Banerji was among the earliest Indians to join the Indian Civil Service (ICS). He successfully passed the ICS exam in 1869 in England and was appointed as an assistant magistrate. Later he was dismissed by the British government on the pretext of a minor procedural issue related to his handling of a case. Many believed that racial discrimination was the real reason behind his dismissal, as British officers were uncomfortable with Indians holding powerful administrative positions. This injustice fueled Banerji’s nationalist spirit, and he dedicated himself to the cause of Indian self-rule. He became a key political leader and co-founded the Indian National Association in 1876 which later merged with the Indian National Congress (INC).

Explanation

When light passes from one medium to another, its speed and direction change due to differences in the refractive indices of the two media. This phenomenon is known as refraction.

Statement 1 is correct: In a denser medium (with a higher refractive index), light travels slower. When light moves into a less dense medium (with a lower refractive index), it speeds up. As a result, the light bends away from the normal (the imaginary line perpendicular to the surface at the point of incidence). The object appears to be closer from the surface than it actually is, as seen in the case of a coin in water when viewed from above.

Statement 2 is correct: If a person is underwater looking at a coin above the surface, the coin appears higher than its actual position, not lower. This is because light bends away from the normal when moving from water (denser) to air (rarer).

Explanation

While regular remuneration for Panchayat members was encouraged in some cases, it was not mandatory under the 73rd Amendment. The Act does not explicitly mandate regular pay for members but rather focuses on ensuring their participation and responsibilities. Some states have implemented this provision, but it is not a constitutional requirement under the 73rd Amendment. Options (a), (b) and (c) are correct:

The 73rd Amendment did indeed assign additional responsibilities to Panchayats, including areas like agriculture, rural development, primary education, and social forestry. The 73rd Amendment mandated that elections be held at regular intervals and that all posts in Panchayats, including the posts of Sarpanch and Ward Members, must be filled through elections. The 73rd Amendment introduced reservation for women in Panchayats, ensuring that one-third of the seats are reserved for women, which was a landmark provision to promote gender equality.

Explanation

Statement 1 is correct: The filament in a light bulb is typically made of tungsten. When the filament is not uniform, the thinner sections tend to heat up more, leading to higher temperatures and stress, which can cause premature failure.

Statement 2 is correct: Light bulbs typically contain an inert gas, like argon, to prevent oxidation of the filament and improve lifespan. Complete evacuation of the bulb is not possible. A small quantity of gases left behind which expands on heating by heat through filament. If the bulb is not evacuated properly, the filament would burn out quickly causing the bulb to have a short life.

Statement 3 is correct: The wires supporting the filament are designed to withstand high temperatures. However if they are not robust enough or if the filament heats up too much, and they can melt, causing the bulb to fail.

Explanation

Statement 1 is correct: Most car batteries are 12-volt lead-acid batteries. This is the standard voltage for automotive applications as it provides sufficient power for starting the engine and running electrical systems in vehicles.

Statement 2 is incorrect: The electrolyte used in a car battery is sulfuric acid (H₂SO₄), not hydrochloric acid. Sulfuric acid is mixed with distilled water to create the electrolyte solution, which facilitates the electrochemical reactions in the battery.

Statement 3 is incorrect: The electrodes in a car battery are made of lead (Pb) and lead dioxide (PbO), not copper. The negative electrode (anode) is made of pure lead, and the positive electrode (cathode) is made of lead dioxide.

Statement 4 is correct: The capacity of a car battery is expressed in ampere-hours (Ah). This unit measures the amount of charge a battery can deliver over time. For example, a 50 Ah battery can theoretically deliver 1 ampere of current for 50 hours or 5 amperes for 10 hours.

Explanation

The statement in Option (c) is incorrect. Navanna is a play written by Nabin Chandra Das, but it is not based on the famine of Bengal. It is a social drama that depicts the conflict between tradition and modernity in Bengali society. Statements in Options (a), (b) and (d) are correct:

Neel Darpan was a play based on the exploitation of Indigo farmers in Bengal by the British planters, written by Dinbandhu Mitra. Ghashiram Kotwal was a famous Marathi play, written by Vijay Tendulkar, which deals with the issues of corruption and power in the context of the Maratha empire. The Parsi theatre influenced the development of Urdu theatre, which gained prominence in the 19th and early 20th centuries.

Explanation

A is matched with 4: The First Indian War of Independence was written by Vinayak Damodar Savarkar. It is a seminal work that describes the 1857 revolt as the first war of Indian independence. B is matched with 3: Anand Math was written by Bankim Chandra Chatterji. It is a famous Bengali novel that inspired the Swadeshi movement and features the iconic patriotic song Vande Mataram. C is matched with 2: Life Divine was written by Sri Aurobindo. The Life Divine explores the evolution of consciousness and the integration of spiritual and material life. D is matched with 1: Sadhana was written by Rabindranath Tagore. It is a collection of essays that reflects his thoughts on humanism and spirituality.